Sekai-ichi Hatsukoi - 1x06 - Season 1, Episode 6- Followmy.tv

After an onsen trip, Chiaki is burned out and can hardly concentrate on work. The emerging love triangle between him, Hatori and Yuu compounds his inability to focus as well. Later on in Chiaki's apartment, Hatori informs him that he must attend an upcoming party because his manga will be made into an anime and he must meet the people in charge. During the party, after meeting the anime staff, Chiaki sees Hatori surrounded by many women, including Ichinose Erika; a top writer who is known to have taken a liking to Hatori. Chiaki, feeling that Hatori is comfortable with the writer, becomes jealous and promptly leaves the party with Yuu. The morning after, Yuu admits to Chiaki that he is in love with someone, but when Chiaki asks who the person is, he simply says that Hatori knows the person well, leaving Chiaki puzzled and confused.